1. Field of the invention
The present disclosure relates to an inverter-charger combined device for electric vehicles and a control method thereof.
2. Description of Related Art
Generally, an electric vehicle includes a high voltage battery charged with a high voltage, e.g., approximately 72 volts, a 3-phase motor driven by a power charged in the high voltage battery to run an electric vehicle, and an inverter for driving the 3-phase motor. However, the driving of the 3-phase motor using the power charged in the high voltage batter is limited by capacity of the high voltage battery.
That is, in a case the power remaining in the high voltage battery of the electric vehicle drops below a predetermined level, the 3-phase motor cannot be driven any longer. Hence, the electric vehicle is equipped with a high voltage charger to charge the high voltage battery. The high voltage charger may be largely classified to two types, i.e., a slow speed charger using a household single AC power, and a high speed charger using a transmission and distribution 3-phase AC power.
Meanwhile, each of the inverter, the high voltage charger and the low voltage charger is separately installed, such that it takes lots of time and man power to respectively install the inverter, the high voltage charger and the low voltage charger on the electric vehicle. Thus, an inverter-charger combined device for electric vehicle is being developed that is combined of the inverter, the high voltage charger and the low voltage charger in one integrated configuration.
However, a power unit applied to a switching element of the inverter-charger combined device is configured in a common power source, and there is no sufficient measure to cope with a situation where the power unit is out of order.